Apparatus for transferring paper sheets between successive printing units

ABSTRACT

Apparatus to transfer paper sheet from a first printing unit to a second printing unit over a cylinder rotatable about its longitudinal axis which is located between the printing unit. A carrier shaft for a set of grippers is journalled beyond the periphery of the cylinder, so as to move conjointly with the cylinder but rotate about its own axis. Mounted on the carrier shaft are a plurality of grippers, each comprising a first member secured to the carrier shaft and a second member rotatable about it. Cam means is provided which on rotation of the cylinder activates one or both of the gripper members to grasp the paper sheet on the first printing unit and carry it to the second printing unit while being supported on the cylinder.

United States Patent [191 J urny et al.

[ 1 APPARATUS FOR TRANSFERRING PAPER SHEETS BETWEEN SUCCESSIVE PRINTING UNITS [75] Inventors: Josef Jurny, Sebranice; Vaclav Sedlak, Jedovnice, both of Czechoslovakia [73] Assignee: Adamovske Strajirny, narodni podnik, Adamov, Czechoslovakia [22] Filed: June 10, 1974 [21] Appl. No.: 477,862

Related US. Application Data [63] Continuation of Ser. No. 267,546, June 29, 1972,

[ Aug. 19, 1975 Primary ExaminerEdgar S. Burr Assistant ExaminerWilliam Pieprz Attorney, Agent, or F irm-Murray Schaffer [57] ABSTRACT Apparatus to transfer paper sheet from a first printing unit to a second printing unit over a cylinder rotatable about its longitudinal axis which is located between the printing unit. A carrier shaft for a set of grippers is journalled beyond the periphery of the cylinder, so as to move conjointly with the cylinder but rotate about its own axis. Mounted on the carrier shaft are a plurality of grippers, each comprising a first member secured to the carrier shaft and a second member rotatable about it. Cam means is provided which on rotation of the cylinder activates one or both of the gripper members to grasp the paper sheet on the first printing unit and carry it to the second printing unit while being supported on the cylinder.

APPARATUS FOR TRANSFERRING PAPER SHEETS BETWEEN SUCCESSIVE PRINTING UNITS This is a Continuation Application of Ser. No. 267,546 filed June 29, 1972, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to apparatus for the transfer of paper sheets in printing presses and in particular to a transfer cylinder for transferring paper sheet between two printing units for multicolor printing whereby the paper sheet is turned for printing on two sides of the sheet. Hitherto known devices for the turning of paper sheets between both printing units generally follow two constructions. In the first, the printing units each have one impression cylinder which has a diameter twice that of the other printing cylinders of the unit. Between these enlarged impression cylinders, there is located a transfer cylinder which is provided with two gripper mechanisms and two suction mechanisms. When the paper sheet is turned, the suction means seize edge of the paper sheet, turn the sheet partially and transfer it into the grippers which thereafter finish the turning and complete the transfer into the grippers of the impression cylinder of the following printing unit.

A disadvantage of the mentioned device is in that the intermediate sheet transfer cylinder is provided with two separate gripper mechanisms and two separate mechanisms. This complicates and makes the apparatus expensive. Further, during the transfer and turning of the sheet for printing on the reverse side, the edge of the paper is engaged by the suction means while being directly on the impression cylinder, and without any possibility of aligning the paper sheet before. Thus registration of the sheet and accurate printing cannot be guaranteed. Of importance also is the fact that the use of suction means itsself does not guarantee a quality transfer of the paper sheet to the gripper mechanism and is in fact the cause of many transfer failures.

In the second construction, the transfer cylinder is also provided with two gripper mechanisms which are arranged on shafts which are controlled by gear transmission mounted on drive shafts. The turning of the paper sheet occurs when the first gripper mechanism seizes the edge of the paper sheet on the first impression cylinder, then swings to the middle of the cylinder and delivers the paper sheet into the grippers of the second mechansim which transfers the paper sheet by a reverse swinging movement to the impression cylinder of the following printing unit. This device is improved over the first described construction as there is provided an ability to align the paper sheet before delivery to the gripper mechanism of the transfer cylinder. A disadvantage of this device lies however in that it has two gripper mechanisms for the transfer of the paper sheet to be printed also on the reverse side, so that while turning the sheet it has to be transferred from one gripper mechanism to the other one. This leads to many failures. Also the device with two gripper mechanisms is more expensive.

It is an object of the present invention to provide a device for the transfer of paper sheets between successive units of a multicolor or perfecting printing press of the rotary type which overcomes the disadvantages and defects of the prior art.

It is an object of the present invention to provide sheet turning apparatus of the type described which is SUMMARY OF THE INVENTION According to the present invention a device or apparatus is provided to transfer paper sheet from a first printing unit to a second printing unit comprising a cylinder rotatable about its longitudinal axis interposed between said units for supporting said sheets during the transfer. A carrier shaft is journalled in means projecting beyond the periphery of the cylinder, to move conjointly with the cylinder but rotate about its own axis.

Mounted on the carrier shaft are a plurality of gripper means, each comprising a first member secured to the carrier shaft and a second member rotatable about it.

The apparatus includes cam means for activating one or both of said gripper members to grasp the paper sheet on the first printing unit and carry it to the second printing unit on rotation of said cylinder.

Preferably, the cylinder is formed of a central shaft, a pair of spaced carrier disks secured thereto at each end and at least one arcuate segmented disk interposed therebetween. The supports for the carrier shaft are radial projections extending from the end-carrier disks. The longitudinal axis of the carrier shaft is journalled along a line parallel to the central shaft and at a distance greater therefrom than the radius of the segmented disks.

According to another feature of the present invention the apparatus is provided with means for reversing the orientation of the grippers so that the sheet may be delivered with one side up for multicolor printing where both sides may be printed.

The apparatus also includes means for selectively activating one or the other or both of the gripper members. The means for doing so comprises a pair of cam systems, including cams, followers and means linking each of the gripper members to the followers for selective predetermined operation.

Full details of the present invention are given in the following disclosure, and are shown in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawings:

FIG. 1 is a view of the transfer cylinder through a longitudinal chord in partial section;

FIG. 2 illustrates a sectional view taken in the plane A-A of FIG. 1 before the paper sheet is seized by the grippers for printing on one side of the sheet;

FIG. 3 is a sectional view taken in the plane B B of FIG. 1 in the same position as shown in FIG. 2;

FIG. 4 is a sectional view taken in the plane A A of FIG. 1 in the position after the delivery of the printed paper sheet from the first printing unit to the impression cylinder of the second unit for multicolor printing on one side of the sheet;

FIG. 5 shows a sectional view taken in the plane C C of FIG. 1 in a position as shown in FIG. 4;

FIG. 6 shows a sectional view taken in the plane A A of FIG. 1 in a position before the seizing of the paper sheet for transfer in an operation for printing on two sides of the sheet; and

FIG. 7 is a sectional view taken in the plane A A' of FIG. 1 in a position before the delivery of the paper sheet to the impression cylinder of the second unit for printing on two sides of the paper sheet.

DESCRIPTION OF INVENTION Briefly as seen in the drawings, particularly FIG. 2, a sheet transfer cylinder 1 is interposed between the impression drum 32 of the first printing unit and the impression drum 33 of a second printing unit. The cylinder is adapted to be rotated by conventional means, as for example counter-clockwise as seen by the arrow, about its central longitudinal axis. Mounted on projections extending radially from the peripheral surface of the cylinder is a shaft 4 on which a series of similar gripper means are arranged. The gripper means, each comprising a pair of associated members, are arranged in a single row and are adapted to grasp the edge of a sheet 31 on the first drum, and hold the same during continued rotation until the sheet reaches the second drum (FIG. 4). The cylinder and grippers are dimensioned so that the sheet is supported on the periphery of the cylinder during the transfer. The gripper means are further, and significantly provided with two cam systems for their activation which permits them to selectively carry the sheet without turning over as seen in FIGS. 2 and 4, when multicolor printing is desired on one side, or in the alternative with reversal of the sides, as seen in FIGS. 6 and 7, when printing on both sides is desired.

The sheet transfer and support cylinder according to the invention consists of a main central shaft 1, on which is securely mounted a left hand carrier disk 2 and a right hand carrier disk 3 between which a plurality of segmented disks 34 are arranged. This arrangement produces a light simple cylinder having minimum surface for interference with the printed sheet. If desired the cylinder may take another form such as a fully covered mesh cylindrical segment, etc. The carrier disks 2 and 3 are each provided on their outer circumferential edge with a projection 41 extending beyond their peripheries in which is rotatably journalled a carrier shaft 4. The longitudinal axis of the carrier shaft 4 is ar ranged at a distance K from the longitudinal axis 43 of the main shaft 1, which distance is larger than the radius R of disk segments 34.

The drum 32 is of conventional design and is provided, as seen in FIG. 2, with a gap in its peripheral surface adapted to receive the gripper means, so that the edge of the sheet 31 may be grasped while still on the drum 32, without the need for suction means to lift the paper, as was required by the prior art, as mentioned in the introduction hereto. It is for this reason that the distance must be larger than the radius R of the transfer cylinder. The drum 33 is similarly formed with a gap in its circumferential surface, to permit on the one hand the introduction of the gripper means, (FIG. 4) as well as its own gripper members for receiving the sheet 31 from the transfer cylinder.

As seen in FIG. 1, on one end (right in FIG. 1) of the carrier shaft 4, there is fixed a pinion 5 which engages with a toothed segment 6 which is fixed on a driving shaft 7 rotatably journalled in the right hand carrier disk 3 and in a drive gear 8 which is securely fixed on the main shaft 1. The gear 8 meshes with a transmission system (not shown) coupled to the main motive means of the printing presses. A crank lever 12 is mounted on one end of the driving shaft 7 and is provided with a pin 36. A spring 11 is hinged with one end to the pin 36 and attached with its other end to a pin 35 fixed in the right hand carrier disk 3. On the other end of the driving shaft 7 there is fixed a lever 9. The lever 9 has a split collar at one end by which it is screwed to the shaft 7. So as to be axially transversable therewith, it carries at its other end an adjustable follower roller 10 of a first cam system. The cam follower roller 10 is mounted on the end of a small axle, mounted within a journal or hole at the end of lever 9. During multicolor printing on one side of the paper sheet the follower roller 10 seats on the functional surface of a cam 13 but is movable axially to bear on the functional surface of a cam 14 when the paper sheet is desired to be turned for printing on its reverse or second side. A right hand flanged bushing 15 is rigidly mounted to the right side frame 16 of the printing machine. The cams 13 and 14 are fixed to the bushing 15 and the cam 14 is provided with arcuate slots in which screws or suitable fasteners are located so that the cam may be adjustably mounted on the bushing 15. The cams 13 and 14 are thus fixed to the side wall 16 of the printing machine and are not movable during printing. According to the required function of the device the axially traversable follower roller 10 is transversely shifted to seat on either cam 13 or respectively, on cam 14. The follower roller 10 moves along the functional surface of the cam 13, or the cam 14 as a result of the movement of shaft 7 on which is fixed the lever 9 carrying the follower roller 10. The shaft 7 is carried by the rotating disk 3 and is revolved with this disk.

On the carrier shaft 4 there are mounted a plurality of spaced fixed grippers 17 in association with each of which are arranged pivotal or swinging grippers l8 rotatable about the shaft 4. The grippers are arranged in right and left hand orientation for multicolor or perfecting printing respectively. The swinging grippers 18 are provided with extending control fingers 39, (FIGS. 2, 4, and 6) on which the rollers 20 of operating levers 21. The operating levers 21 bear are adjustably mounted by means of screws 40 on a control rod 22 which is rotatably journalled with one end in the left hand carrier disk 2 and with the other end in the right hand carrier disk 3 parallel to the central shaft axis 1. To the free or rear end of each of the fixed grippers 17, there is fixed one end of a spring 19 which is attached at its other end to the free or rear end of the associated rotatable gripper 18 (FIG. 2). The main shaft 1 which is provided with the disk segments 34 is journalled at one end in a bearing 44 in a left hand flange bushing 29 and at its other end in a bearing 45 in the right hand flange bushing 15. On the opposite or left end of the control rod 22 is fixed a lever 23 which is provided with an axially traversable roller 24 cooperating with a second cam system. The roller 24 is mounted in the same manner as roller 10. The traversable roller 24 seats, during multicolor printing on one side of the paper sheet on the functional surface of cam 28 which is fixed to the left hand bushing 29, but when it is desired to turn the paper sheet for printing on the reverse side, the roller 24 seats on the functional surface of a cam 27 the roller being mounted for adjustable transverse movement on the left hand bushing 29 which is fixed to a left side frame 30 of the printing machine. On the control shaft 22 there is fixed a lever 26 which is provided with an extending pin 38, on which is hinged one end of a spring 25 which is attached at the other end to a pin 37 fixed in the left hand carrier disk 2.

As seen in FIG. 2 the transfer cylinder 3 with the disk segments 34 is arranged between the transfer drum 32, receiving the sheet from the first printing unit (not shown) and an impression drum 33 of the following or second printing unit. Between the drive gear 8 and the right bearing 45 of the right hand flange bushing there is mounted a spacer sleeve 46.

The device operates as follows during multicolor printing on one side of the sheet:

On initiation of the transfer cycle the grippers 17 and 18 are opened widely, the cam system being set so that their cam followers 10 and 24 ride on cams 13 and 28 respectively. The cam systems are such that the grippers open upwardly in opposition to the direction of movement of the transfer drum 32. A sheet 31 printed on its reverse side is delivered from the first printing unit to the transfer drum 32 moving in a clockwise direction. (FIGS. 2 and 4). The transfer cylinder 3 rotates counter-clockwise causing simultaneous rotation of the carrier shaft 4 which closes the grippers 17 against grippers 18 whereby they seize the paper sheet 31. The paper sheet 31 is thus taken from the transfer drum 32 and carried on surfaces of the disks, to the impression drum 33. After delivery of the sheet to drum 33 the grippers 18 and the fixed grippers 17 are caused to open (FIG. 4) leaving the sheet on the impression cylinder 33 with the same side ready for printing. The impression cylinder 33 also moves in a clockwise direction.

The functional motion of the grippers 17 is derived from the cam 13 (FIG. 3), on the functional surface of which the traversably movable follower roller 10 of the lever 9 is made to ride. Due to the swinging movement of the lever 9 caused by the contour of cam 13, the drive shaft 7 is rotated carrying with it the toothed segment 6 which in turn rotates the pinion 5 fixed on the end of the carrier shaft 4, so that the grippers 17 are swung. The contour of cam 13 is such that while seizing the paper sheet 31, the grippers 17 seat against the swing grippers 18. The grippers 18 are maintained with their paper engaging surfaces in a tangential position to the periphery of the transfer cylinder by the action of their own cam system. The movement of the swing grippers 18 is derived from the cam 28, on the functional surface of which the traversable follower roller 24 of the lever 23 rides. Lever 23 is fixed on the control rod 22, on which are mounted the radial control arms 21 whose rollers cooperate with the control fingers 39 to locate the swing grippers 18. The cam 28 is contoured to maintain the gripper l8 fixed in the tangential position during the transfer operation in order that the sheet 31 is properly carried along the periphery of the transfer cylinder 3. By the further rotation of the transfer cylinder 3 the paper sheet 31 is thus carried to the impression drum 33 (see FIG. 4). The carrier shaft 4 is thereafter further turned as a result of the contour of cam 13 so that the fixed grippers 17 open and deliver the paper sheet 31 into the not illustrated grippers of the impression drum 33 with the same side up to be printed on the same side with another color. Continued turning of the transfer cylinder and the movement of the traversable follower roller 24 on the functional surface of the-cam 28 causes the swing grippers 18 to be swung from the tangential position. The carrier shaft 4 with the fixed grippers 17 also rotate to a corresponding position as at the beginning of the cycle to seize the following paper sheet 31.

For printing where the paper sheets are to be printed on both the obverse and on the reverse sides, the device operates as follows:

The operator manually sets the traversable roller 10 and 24 from the cams 13 and 28 respectively onto the functional surface of the cams 14 and 27, with a tool for loosening a set screw (not shown) respectively. This results in the movement of the swing grippers 18 rather than the fixed grippers 17 so that they bear on the grippers 17 fixed on shaft 4 by which the trailing edge of the paper sheet 31, which was already printed on one side (obverse) is seized. (See FIG. 6). By rotation of the transfer cylinder 3 and simultaneous rotation of the carrier shaft 4 by the action of roller 10 on the cam 14, the grippers 17 and the grippers 18 holding the printed paper sheet 31 are turned in a position tangential to the periphery of the transfer cylinder 3 facing in the direction of movement. The contours of cams 13 and 28 and 14 and 27 are chosen according to function, that is, for perfecting printing or multicolor printing respectively. On the shifting of the rollers 10 and 24 the position of grippers 17 and 18 reverse themselves as seen in a comparison of FIGS. 2 and 6. The roller elements 20 are thus made to bear against the opposite projections 39. This permits the transfer of the sheet without changing the direction of movement of either the drum 32 or the drum 33 of the printing units. In this case, as will be seen in FIG. 6, the grippers grasp the tail end of the sheet 31, peeling it off the surface of drum 32 andreversing its faces, in comparison with the operation shown in FIGS. 2 and 4.

When the printed paper sheet 31 is transferred to the impression drum 33, the fixed grippers 17 open, whereby the swing grippers 18 remain in a tangential position to the periphery of the transfer cylinder 3, and the printed paper sheet 31 is delivered into not illustrated grippers of the impression cylinder 33 of a following printing unit to be printed also on the reverse side. By further turning of the transfer cylinder the swing grippers 18 open and then close to bear on the fixed grippers 17 which are rotated to the initial position to be able to seize a following paper sheet.

From the foregoing it will be seen that an advantage of the present invention is in the fact that the transfer cylinder 3 is provided with only one set of gripper mechanism which serves for both the gripping of the paper sheets during printing on one side of the sheet, since as in multicolor printing, as well as for turning the sheet when it is to be printed on the reverse side, that is, perfecting printing. The transfer and/or the turning -of the paper sheet is achieved by only one set of grippers guarantying a good registered print and accurate alignment, since the sheet is not transferred from gripper to gripper during movement. The arrangement of the device with only one set of gripper mechanisms enables a construction of more simple parts, consequently, the whole device is cheaper in production than the heretofore known devices. The arrangement of the present device also permits as easy change of operation of the printing machine from printing on one side to the printing on both sides of the paper sheet, so that precious operating time is saved. A substantial advantage also lies in the fact that the construction of the transfer cylinder enables adjustment of the gripper mechanisms independently of the transfer cylinder.

Various modifications and embodiments will of course be evident to those skilled in this art. Accordingly, the foregoing disclosure is to be taken as illustrative only, and not limiting of the scope of the present invention.

What is claimed is:

1. Apparatus for use in a multicolor and perfecting printing press to transfer paper sheet from a first rotating drum to a second rotating drum, comprising a rotatable cylinder disposed between said drums for supporting said sheets during the transfer, projecting support means located on said cylinder and extending radially beyond the periphery of said cylinder, a carrier shaft joumalled in the outer ends of said support means and rotatable about its own longitudinal axis and movable conjointly with said cylinder, a plurality of gripper means for gripping and transferring said sheet from said first to said second drum spaced along said carrier shaft, said gripper means comprising a first gripper member fixed on said carrier shaft and a second gripper member rotatable thereabout, a pinion secured at one end of the carrier shaft, said pinion engaging a swingable toothed segment, said segment being joumalled on said cylinder for rotation about an axis eccentric of the cylinder axis, a lever arm fixed at one end to said segment and extending therefrom parallel to the cylinder axis, a first cam follower traversably mounted at the end of said lever and a first pair of cams each having a contour adapted to be selectively engaged by said first cam follower to reciprocate said segment thus causing said carrier shaft to rotate about its longitudinal axis and thus orienting said first and second gripper members to selectively engage the leading or trailing edge of said paper sheet on said first drum, and means for activating said second gripper member in either orientation to cause said gripper members to grasp said paper sheet and carry the same on rotation of said cylinder between said first drum and said second drum, said paper sheet being selectively transferred to said second drum without turning over for multicolor printing or with turning over for perfecting printing.

2. The apparatus according to claim 1 wherein said means for activating said second gripper comprises a control rod joumalled between said cylinder and spaced parallel to said carrier shaft and having means mounted on said control rod extending into engagement with said rotatable second gripper members for controlling the operation of said second gripper, and a second cam follower traversably linked to said control rod and a second pair of cams each having a contour adapted to be selectively engaged by said second cam follower to swing said control rod in opposite directions about its longitudinal axis to cause said control means to engage said second gripper members.

3. The apparatus according to claim 1 wherein said cylinder comprises a central shaft, a carrier disk fixedly secured at each end of said shaft and at least one arcuate disk secured to said shaft therebetween, the carrier shaft joumalled at each end in the carrier disks and its longitudinal axis being parallel to said central shaft and at a greater distance from the longitudinal axis of said central shaft than the length of the radius of said arcuate disk.

4. The apparatus according to claim 2 wherein said first pair of cams is mounted on the side of the printing machine opposite to that of the second pair of cams.

5. The apparatus according to claim 3 wherein the axle on which said toothed segment is fixed is rotatably joumalled in one of the carrier disks and in a drive gear fixed on the main shaft of said cylinder and includes a pin secured to said axle, a spring attached at one end to said pin and at the other end to a pin fixed in said one carrier disk.

6. The apparatus according to claim 4 wherein the first traversable cam follower seats while multicolor printing on one side of a sheet on the functional surface of one of said cams in its associate pair which is fixed on a bushing rigidly mounted to the machine about said main shaft and said first traversable cam follower seats when the paper sheet is turned for printing on the reverse side on the functional surface of the other cam in its associated pair.

7. The apparatus according to claim 4 wherein said second traversable cam follower seats while multicolor printing on one side of a paper sheet on the functional surface of one of the cams in its associated pair fixed to a bushing rigidly secured to the printing machine and the second transversable cam follower seats while turning of a paper sheet for perfecting printing on the other cam of its associated pair.

8. The apparatus according to claim 7 wherein the control rod is provided with a fixed lever which is provided with a pin, on which is hinged one end of a spring which is attached at the other end to a pin which is fixed in the adjacent carrier disk. 

1. Apparatus for use in a multicolor and perfecting printing press to transfer paper sheet from a first rotating drum to a second rotating drum, comprising a rotatable cylinder disposed between said drums for supporting said sheets during the transfer, projecting support means located on said cylinder and extending radially beyond the periphery of said cylinder, a carrier shaft journalled in the outer ends of said support means and rotatable about its own longitudinal axis and movable conjointly with said cylinder, a plurality of gripper means for gripping and transferring said sheet from said first to said second drum spaced along said carrier shaft, said gripper means comprising a first gripper member fixed on said carrier shaft and a second gripper Member rotatable thereabout, a pinion secured at one end of the carrier shaft, said pinion engaging a swingable toothed segment, said segment being journalled on said cylinder for rotation about an axis eccentric of the cylinder axis, a lever arm fixed at one end to said segment and extending therefrom parallel to the cylinder axis, a first cam follower traversably mounted at the end of said lever and a first pair of cams each having a contour adapted to be selectively engaged by said first cam follower to reciprocate said segment thus causing said carrier shaft to rotate about its longitudinal axis and thus orienting said first and second gripper members to selectively engage the leading or trailing edge of said paper sheet on said first drum, and means for activating said second gripper member in either orientation to cause said gripper members to grasp said paper sheet and carry the same on rotation of said cylinder between said first drum and said second drum, said paper sheet being selectively transferred to said second drum without turning over for multicolor printing or with turning over for perfecting printing.
 2. The apparatus according to claim 1 wherein said means for activating said second gripper comprises a control rod journalled between said cylinder and spaced parallel to said carrier shaft and having means mounted on said control rod extending into engagement with said rotatable second gripper members for controlling the operation of said second gripper, and a second cam follower traversably linked to said control rod and a second pair of cams each having a contour adapted to be selectively engaged by said second cam follower to swing said control rod in opposite directions about its longitudinal axis to cause said control means to engage said second gripper members.
 3. The apparatus according to claim 1 wherein said cylinder comprises a central shaft, a carrier disk fixedly secured at each end of said shaft and at least one arcuate disk secured to said shaft therebetween, the carrier shaft journalled at each end in the carrier disks and its longitudinal axis being parallel to said central shaft and at a greater distance from the longitudinal axis of said central shaft than the length of the radius of said arcuate disk.
 4. The apparatus according to claim 2 wherein said first pair of cams is mounted on the side of the printing machine opposite to that of the second pair of cams.
 5. The apparatus according to claim 3 wherein the axle on which said toothed segment is fixed is rotatably journalled in one of the carrier disks and in a drive gear fixed on the main shaft of said cylinder and includes a pin secured to said axle, a spring attached at one end to said pin and at the other end to a pin fixed in said one carrier disk.
 6. The apparatus according to claim 4 wherein the first traversable cam follower seats while multicolor printing on one side of a sheet on the functional surface of one of said cams in its associate pair which is fixed on a bushing rigidly mounted to the machine about said main shaft and said first traversable cam follower seats when the paper sheet is turned for printing on the reverse side on the functional surface of the other cam in its associated pair.
 7. The apparatus according to claim 4 wherein said second traversable cam follower seats while multicolor printing on one side of a paper sheet on the functional surface of one of the cams in its associated pair fixed to a bushing rigidly secured to the printing machine and the second transversable cam follower seats while turning of a paper sheet for perfecting printing on the other cam of its associated pair.
 8. The apparatus according to claim 7 wherein the control rod is provided with a fixed lever which is provided with a pin, on which is hinged one end of a spring which is attached at the other end to a pin which is fixed in the adjacent carrier disk. 